. The project is to develop a high-frequency in-the-ear speaker and microphone for auditory research with sensitivities up to 100 kHz. The speaker will be able to produce at least 100 dB SPL in a coupled environment and feature a flat frequency response from 1 kHz to 100 kHz. The microphone will be wide-bandwidth, matching that of the speaker and will have sufficient sensitivity (5 mV/Pa) and low noise level (<10 dB SPL) for calibrating in the ear signals and for performing studies with otoacoustic emissions. The speaker and microphone housings will be designed so that they can be easily coupled to a wide range of ear sizes of experimental animals. The speaker and microphone will be developed with electrostatic technology that provides the wide-bandwidth required. PROPOSED COMMERCIAL APPLICATION: High frequency speaker and microphone for research applications.